My build is probably one of the simplest implementations of this pre-amp that exists and it is doing exactly what I wanted.
The time has come for me to replace my highly customised high end case (don't get to envious please ), with something slightly more permanent (and maybe even better looking ).
As per my current case, I am looking to semi-expose the valves (tubes), and I am looking for any feedback on the size cut-outs others have used for the valve openings. I used 38mm dia (just under 1 1/2 inches in that strange measurement system), but am thinking that these may be better being a bit bigger, to aid air flow / heat dissipation, particularly for the rectifier.
A couple dodgy photo's are attached.